1. Field of the Invention
The present invention relates generally to surgically implanted gastric bands for encircling the stomach having a releasable securing appendage. A method for treating morbid obesity utilizing a releasably-securable gastric banding device is also disclosed.
2. Description of the Related Art
A belt-like gastric band for encircling the stomach to control morbid obesity is disclosed by Vincent in U.S. Pat. No. 5,601,604, incorporated herein by reference. The band comprises a belt that can be passed around the stomach and locked into an encircling position in order to create a stoma opening within the stomach. An adjustable portion of the band comprises an inflatable member, which permits fine adjustment of the stoma opening after the stoma is created by locking the band in place. The stoma opening may be adjusted by adding or withdrawing a fluid into or from an inflatable member. The means for injecting the fluid into the inflatable member usually comprises a fill port located beneath the skin that can be accessed extracorporeally by transdermal injection. Thus, following implantation, the gastric band can be adjusted to enlarge or reduce the stoma as required.
The gastric band is implanted surgically, via laparoscopy or laparotomy, and may involve placement of a calibrating apparatus in the stomach to position the stoma and size the pouch created above the stoma. The gastric band is imbricated in position about the stomach to prevent slippage, usually by gastro-gastric sutures (i.e. tissue is wrapped over the band and sutured to itself).
As disclosed by Vincent, the inflatable member or shell is preferably substantially coextensive with an inner stomach-facing surface of the gastric band. Furthermore, it has been observed that the inflatable member should not wrinkle or fold when adjusted, so as to present a substantially smooth contour along the inner circumference. This ensures not only that stomach tissue will not be pinched by the inflatable member, which could lead to discomfort or necrosis, but also protects the shell from a phenomenon known as crease fold failure, which may occur if it is inflated beyond its intended range of adjustment or if the shell is not formed in a toroidal or circular shape.
In use, it has been observed that current gastric bands cannot be easily released once they are locked in place around the stomach to form the stoma. This can be a significant setback for a surgeon attempting to move a gastric band after implantation. In particular, a patients' physiology or change in physiology may necessitate moving the band after initial placement. Other factors that could require moving or releasing the band include a patient's inability to control food intake.
In instances where the band has slid out of place, is improperly placed, or where changes in patient physiology require movement of the band, the currently known gastric bands do not provide for releasing the locking means that hold the band securely around a patient's stomach. While some devices may ultimately be releasable, such devices typically require exertion of considerable force, which can cause damage to or failure of the band. Further, when manipulating the band laparoscopically, the amount of force that can be applied during such a procedure is very limited.
One gastric banding device that appears to have some ability to be locked and unlocked has been marketed under the name HELIOGAST®. The Heliogast band is an inflatable gastric band having an inflatable locking means attached to the tail and which is inserted into a loop attached to the head of the band. After implantation, the band must be inflated to lock the band in place. In theory, this band could be re-opened after placement to allow a medical professional to reposition the band. However, it suffers from the drawback that it must be inflated to lock into position and therefore it must be deflated before being opened and moved. The requirement that the band must be inflated to lock also limits the range of the stoma opening that can be achieved by such a band, as the band must necessarily have a certain amount of liquid pressure inside the band in order to lock. Consequently, the range of adjustment of the Heliogast band is limited in comparison with the band of the present invention, which can be locked regardless of its inflation level. In addition the band can be opened by application of a smaller force than those of the prior art. The smaller force's ability to overcome the locking mechanism increases the possibility of the band unlocking accidentally, such as during vomiting by the patient.
Accordingly, there is a need for a releasable gastric band that can be releasably locked in place around a patient's stomach, released or unlocked to reposition the gastric band on the patient's stomach (or remove the band altogether), and then secured in place again around the patient's stomach. There is further a need for a releasably-securable gastric band that does not require deflation before being released, and which may be locked in place without subsequent inflation of the locking means. Additionally, there is a need for a gastric band that resists being unlocked by normal physiological forces
There is also a need for an adjustable gastric band with increased ease of use when compared to those currently on the international market, specifically a gastric band that has high tensile force resistance along the band, while being able to be opened with reduced force.
Various other objects, advantages and features of the present invention will become readily apparent from the ensuing description and the novel features will be particularly pointed out in the appended claims.